According to the prior art, aerostatic bearing elements are highly suitable for moving and guiding bodies with minimal friction. An aerostatic bearing element is described, for example, in U.S. Pat. No. 7,207,720 in which a body which is porous for gas is arranged at a bearing body and pressurized gas is supplied to the body. A load-carrying gas cushion is formed in the bearing gap between adjacent bearing surfaces. In order to adjust the correct operating point and to specifically influence the characteristics of the aerostatic bearing element, it is necessary, for example, to provide the aerostatic bearing element with preloading. Vacuum preloading, as it is called, in which vacuum-drawing zones are provided within the sliding surface of the aerostatic bearing element, is known from the prior art. For this purpose, the bearing body is provided with bore holes or channels which are then connected to a negative-pressure pump. A state of equilibrium having a positive influence on the mechanical properties of the aerostatic bearing element is formed between the sliding surface of the aerostatic bearing element operating at positive pressure and the preloading unit operating at negative pressure. An aerostatic bearing element disclosed in U.S. Pat. No. 4,749,283 is suitable for a vacuum environment. In this case, the suction stages surrounding the sliding surface or load-carrying zone are provided for the excess gas at the sliding surface so that the gas does not invade the vacuum environment. Further, aerostatic bearing elements are used in gas-guided stages for electron beam lithography as is disclosed, for example, in EP 1 235 115 A2.
Vacuum preloading, mentioned above, for the use of aerostatic bearing elements under normal atmosphere cannot be implemented under vacuum conditions. Therefore, aerostatic bearing elements are frequently preloaded by mass, or opposed arrangements of bearing elements are selected and preloading is carried out by the wrap-around.